Originally posted by the Voice of America. Voice of America content is produced by the Voice of America, a United States federal government-sponsored entity, and is in the public domain. Blast Kills 39 at Wedding in Southern Afghanistan VOA News 09 June 2010 An official in southern Afghanistan says a blast has killed 39 people and wounded more than 70 at a wedding in Kandahar province. The official says the explosion hit Wednesday in the Arghandab district. The cause of the blast was not immediately known. In neighboring Helmand province, Taliban militants shot down a NATO helicopter, killing four U.S. soldiers. The Taliban says it used rocket-propelled grenades against the aircraft, which was flying in the Sangin district. Afghan officials say the helicopter was flying at a low altitude to support ground troops. Pentagon spokesman Bryan Whitman said the incident reflects increased operations by both NATO forces and the Taliban. Elsewhere in Helmand, the British Defense Ministry says an explosion killed a British soldier Wednesday in the Nahr-e Saraj district.  A series of attacks in Afghanistan has killed 18 NATO troops since Monday. U.S. Defense Secretary Robert Gates said Wednesday he expects to see signs of progress in Afghanistan by the end of the year. He said the top NATO and U.S. military commander in Afghanistan, General Stanley McChrystal, has assured him that enough progress will be made to justify a continued presence in the country. But Gates also warned of a "very tough summer" of violence as U.S. forces push deeper into Kandahar. The Taliban has increased attacks as NATO seeks to drive the group from its stronghold in the south. Some information for this report provided by AP and AFP. .